Valve systems

ABSTRACT

A valve system for a liquid-containing vessel such as a boiler in which a valve chamber between connections leading to the vessel, to a control device and to exhaust contains a valve head which can close the connections to the vessel and to exhaust but can not close the connections to the control device.

United States Patent Robert S. Williams Upper Arley, near Bewdley,England 761,650

Sept. 23, 1968 Feb. 16, 1971 G.W.B. Boilers Limited Dudley, EnglandSept. 23, 1967 Great Britain lnventor App]. No. Filed Patented AssigneePriority VALVE SYSTEMS 8 Claims, 4 Drawing Figs.

US. Cl 137/386, 251/266 Int. Cl Fl6k 31/50 Field ol'Search 137/156, 213,237, 245, 386, 389, 390, 391; 251/264, 266,

Primary Examiner-William F. ODea Assistant Examiner-David R. M atthew'sAttorney-Sherman and Shalloway ABSTRACT: A valve system for aliquid-containing vessel such as a boiler in which a valve chamberbetween connections leading to the vessel, to a control device and toexhaust contains a valve head which can close the connections to thevessel and to exhaust but can not close the connections to the controldevice.

BACKGROUND OF THE INVENTION l. Field of the Invention This inventionrelates to equipment comprising, in combination, a vessel for containinga liquid, a pipe connecting said vessel to a device for controlling thesupply of liquid to said vessel to maintain the liquid in the vessel ata substantially constant level and a valve located in the pipe betweenthe vessel and the control device, which valve is arranged to controlthe flow of liquid between the control device and the vessel and betweenboth the control device and the vessel and exhaust. i

The present invention has particular application to equip ment of theabove kind in which the vessel is a steam boiler and the valve in thepipe between the boiler and the control device is operable for theremoval of sediment or other solid impurities from the pipe.

2. Description of the Prior Art In a known arrangement in which there isa connection between the top of the boiler and the top of the controldevice whereby the pressure in the control device is the same as that inthe boiler, the valve is arranged so that, during normal operatingconditions, the control device and the boiler are in communication witheach other whereas, when it is desired to remove the, sediment or otherimpurities, the valve is operated so as toconnect the control device toexhaust whereby impurities in the pipe between the valve and the controldevice are blown out of the pipe and the valve is also operated toconnect the interior of the boiler to exhaust to blow out any impuritiesin the pipe between the boiler and the valve.

With an arrangement as described above the control device controls notonly the supply of water to the boiler but also controls operation of aburner that supplies heat to the boiler, the arrangement being thatwater is supplied to the boiler when the level of water in the controldevice falls below a predetermined value and also that heat is suppliedto the boiler so long as the level of water in the control device isabove a predetermined level.

There is a possibility that, with the previous forms of equipment, thevalve can be left in a condition in which the control device is cut offboth from the interior of the boiler and from exhaust. This means that,regardless of the level of the water in the boiler, there will be asubstantially fixed level of water in the control device so that nofurther water will be pumped into the boiler but the burner willcontinue to operate with the danger that the boiler will boil dry. Thecontrol device may consist of a chamber containing a float valve or itmay include electronic or other level sensing devices.

It is an object of the present invention to provide a new or improvedform of equipment of the above kind, more particularly to provide aboiler in which the valve in the pipe connecting the interior of theboiler to the control device is such that the control device cannot beblanked off.

SUMMARY OF THE INVENTION The present invention provides equipment of thekind referred to above in which the valve between the vessel and thecontrol device comprises a valve body containing a chamber, a pair ofvalve seats within the valve chamber, which valve seats are locatedbetween connections to the vessel and to exhaust. a connection to thecontrol device leading from the valve chamber between the valve seats,and a valveoperating member comprising a stem and a head, the head ofthe valve-operating member being movable between a pair of limitingpositions in each of which it is in engagement with one of the valveseats to close either the connection to the vessel or the connection toexhaust and the valve head being arranged so that, in each limitingposition and in any intermediate position, it does not close theconnection to the control device.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an end view of part of a boiler and a valve system connectedthereto;

FIG. 2 is a sectional view of one of the valves;

FIG. 3 is a sectional view of another of the valves; and

FIG. 4 is a sectional view of an alternative form of valve to that shownin FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the arrangement shown inFIGS. 1 to 3, there is provided a generally conventional steam boiler 10which includes a cylindrical shell 11 arranged with its axis horizontal,the shell containing means (not shown) for heating water inside it. Oneach side of the shell 11 and externally thereof there is provided afloat chamber, 12, only one such chamber 12 being shown in FIG. 1, eachchamber l2 containing a float valve (shown in outline in FIG. 1) which,when the level of the water in the chamber is above a predeterminedlevel, cause a burner (not shown) for supplying heat to the boiler to beoperative and the float valve also controls operation of a pump (notshown) for feeding water into the boiler when the level of water in thefloat chamber falls below a predetermined level. Other forms of levelcontrol devices e.g. electronic sensing devices (shown in outline inFIG. I), may be provided.

A pipe 13 connects each float chamber 12 to the interior of the boiler,the two pipes 13 leading to the two chambers 12 being diametricallyopposite to each other and at the same horizontal level. Each pipe 13includes a horizontally extending portion 14 leading to a valve body 15and a vertically extending portion 16 leading from the valve body 15,the valve body 15 being provided with flanges 17 for connection to saidtwo portions 14 and 16 of the pipe.

The valve body 15 contains a generally elongated chamber 18 and at eachend of the chamber 18 there is a valve seat 19 constituted by astainless steel or plastics ring. The connection 20 to the boiler leadsfrom the chamber 18 from one end thereof and, beyond the other valveseat 19 there is fitted an extension piece 21 which has an outlet 9extending at right angles to the axis of the chamber 18. Between the twovalve seats 19 there is a connection 22 extending from the chamber, saidconnection 22 being vertically disposed and arranged in communicationwith the float chamber 12. There is a valveoperating member 23 whichcomprises a stem 24 and a head 25, the head being 'of generally circularcross section and having a projecting lug 26 which is arranged to engagein a keyway 27 in a wall of the chamber 18 whereby the head 25 isprevented from rotating within the chamber and the diameter of the head25 is the same as the diameter of thevalve chamber 18. The stem 24 ofthe valve-operating member 23 is of less diameter than the head 25 andthe head 25 has generally inclined end portions 28 which are arranged toengage the stainless steel or plastics sealing members 19. The length ofthe head 25 is less than the diameter of the connection 22 to the floatchamber 12.

The stem 24 and the head 25 of the valve-operating member 23 areprovided with a blind bore 29 which is threaded over a major portion ofits length and the thread of the operating .member cooperates with amating screw thread formation formed on an operating spindle 30 receivedin the bore 29 whereby, on rotation, of the spindle 30 thevalve-operating member 23, because it is prevented from rotating, byvirtue of the engagement of the lug 26 in the keyway 27, is caused tomove longitudinally within the chamber 18. Rotation of the spindle 30 isobtained by means of a manually operable handle 31 at the free end ofthe spindle 30 the spindle 30 passing through an aperture formed in awall 32 of the extension piece 21 connected to the valve chamber 18 andsealing means 33 being provided between the spindle 30 and said wall 32to prevent the escape of water or steam between the spindle 30 and saidwall 32.

In use the valve-operating member I3 is in one limiting position asshown in chain-dotted lines in FIG. 2 so that one inclined end portion28 of the head 25 of the operating member is in engagement with thevalve seat 19 associated with the outlet 9 leading to exhaust wherebythe boiler 10 and the float chamber 12 are in communication with eachother. When it is desired to remove solid impurities from the pipe 13between the boiler and the float chamber 12 the handle 31 at the end ofthe stem 30 is rotated to move the valve-operating member 23 axiallywithin the chamber 18 out of engagement with said valve seat 19 intoengagement with the valve seat 19 associated with the boiler as shown infull lines in FIG. 2. When the valve head 25 is in an intermediateposition between the two valve seats 19 the connections to the boiler10, the float chamber 12 and exhaust are all open so that impurities areblown out through the outlet 9. When the valve-operating member 23 is inits other limiting position, i.e. in engagement with the valve seat 19associated with the boiler 10, the float chamber 12 is in communicationwith the exhaust whereby the float chamber 12 is emptied and the supplyof heat to the boiler is thereby cut off. This arrangement ensures thatthe float chamber 12 is either in communication with the boiler 10 or incommunication with the exhaust so that there is no possibility of thelevel of water in the float chamber 12 being higher than the level ofthewater in'the boiler 10.

As mentioned above, there is a line 35 connecting the top of the boiler10 to the top of each float chamber 12 for the supply of steam from theboiler to each float chamber 12, whereby, in use, the pressure in eachfloat chamber 12 will be the same as that within the boiler, 10.

There is a single pipe 36 extending from the top of the boiler 10 to aT-junction 37 to which pipes 38 leading to the two float chambers areconnected and there is a valve 39 located between the boiler 10 and theT- junction 37. Said valve 39 is in the form of a cock and, as shown inFIG. 3, includes a shutoff member 40 movable either into or out ofengagement with a valve seat 41 constituted by the surrounds of anaperture 42 formed in a web 43 dividing the interior of the valvechamber 44 into two compartments. In use, the shutoff member 40 isnormally out ofengagement with said seat 41 to allow the flow of steamfrom the boiler 10 to the T-junction 37, the shutoff member 40 being inengagement with a further seat 45 located at the inner end of asubsidiary chamber 46 through the end wall 47 of which projects aspindle 48 for operating the valve. There is a bleed 49 leading fromsaid subsidiary chamber 46 and the arrangement is that, when the valvemember 40 is moved to the position shown in FIG. 3 to shutoff theconnection between the boiler I and the T-junction 37 bleed 49 is incommunication with the subsidiary chamber 46 of said valve and thus incommunication with the atmosphere through the bleed 49. The bleed 49contains a whistle so that, when the valve is operated to shut offtheconnection between the boiler and the T-junction 37, steam from thefloat chamber 12 and the pipe between the T-junction 37 and the floatchamber 12 issues through said bleed 49 to indicate to the operator thatthe valve is closed. The bleed 49 may alternatively contain a pressureor temperature control for sounding a remote alarm. This arrangementalso ensures that should the steam in the line 35 between the T-junction37 and each float chamber 12 condense, the pressure inside the floatchambers 12 will not fall below atmospheric pressure as might causewater to flow from the inside of the boiler 10 into the float chambers12 and therefore give a false reading of the level of water inside theboiler 10.

The valve shown in FIG. 4 may, in some circumstances, be used insteadofthe valve shown in FIG. 2 and includes a flange 50 for connection tothe pipe 14 leading from the boiler and a flange 51 for connection tothe pipe 16 leading to the float chamber 12. The flanges 50 and 51 areat the outer ends of cylindrical tubes 52 and 53 respectively and, atthe junction of the two tubes 52 and 53 there is a generally cylindricalchamber in which the head 54 ofa valve-operating member is located. Thevalve-operating member also includes a stem 55 and a handle (not shown)such as 31 shown in FIG. 2 provided for rotating the stem whereby thehead 5% can be moved between the position shown in full lines in FIG. 4and the position shown chain-dotted in FIG. 4. The valve of FIG. 4 alsoincludes a tube 56 leading to an outlet 57.

The inner ends of the tubes 52, 53 and 56 can be considered asconstituting valve seats and the head 54 of the valve-operating memberis formed with a peripheral recess 58 which extends through an angle ofA projecting member (not shown) fixed to the stem 55 is arranged toengage stops carried by the valve housing whereby the operating memberis prevented from being rotated anticlockwise beyond the positionshownin full lines in FIG. 4 and prevented from being rotated clockwisebeyond the position shown chain-dotted in FIG. 4.

In normal operation of the boiler the head 54 is in the position shownin FIG. 4 whereby the interior of the boiler communicates with the floatchamber 12 through the recess 58 in the periphery of the head 54. Whenit is required to clean the pipe 13 extending between the float chamber12 and the interior of boiler, the valve-operating member is rotated inthe clockwise direction viewed in FIG. 4 whereby the recess 58 is movedinto the position shown in chain-dotted lines and the connection to theinterior of the boiler is shut off and communication between the floatchamber 12 and exhaust is established. It is to be noted that,regardless of the position of the head 54, the float chamber 12 is atall times in communication with either the interior of the boiler orexhaust and that, when the head 54 is not in one of itslimitingpositions, the interior of the boiler can communicate directly withexhaust through the recess 58.

The valve shown in FIG. 4 thus operates in substantially the same way asthe valve shown in FIG. 2.

Each float chamber 12 may include a level-indicating device such as asight glass (not shown). Alternatively there may be a separatelevel-indicating device which is connected to the interior of the boilerthrough a valve the construction of which is either as shown in FIG. 2or as shown in FIG. 4.

A preferred embodiment of the invention having been described, which isset forth by way of example only and not intended to limit the inventionto which modifications evidencing a reasonable range of equivalents willbecome apparent to those skilled in the art.

I claim:

1. In equipment comprising a vessel for containing a liquid, a pipeconnecting said vessel to a control device for controlling the supplyofliquid to said vessel to maintain the liquid in the vessel at asubstantially constant level, an exhaust outlet and a valve located inthe pipe between the vessel and the control device, which valve isarranged to control the flow of liquid between the control device andthe vessel and between both the control device and the vessel andexhaust, the improvement wherein the valve comprises a valve bodycontaining a chamber, a pair of valve seats within the chamber, whichvalve seats are located between the interior of the chamber andconnections to the vessel and to exhaust, a connection to the controldevice leading from the valve chamber between the valve seats, and avalve-operating member comprising a stem and a head, the head beingmovable between a pair of limiting positions in each of which it is inengagement with one of the valve seats to close either the connection tothe vessel or the connection to exhaust and the valve head beingarranged so that, in each limiting position and in any intermediateposition, it does not close the connection to the control device.

2. Equipment according to claim 1 wherein the valve chamber is ofelongated form with the valve seats located one at each end of thechamber and the valve-operating member is movable axially of thechamber.

3. Equipment according to claim 1 wherein the valve chamber is ofgenerally cylindrical form with the valve seats located diametricallyopposite each other, the head of the valve-operating member beingrotatable between its limiting positions and stop means being providedfor preventing movement of the operating member beyond its limitingpositions.

4. Equipment according to claim 1 wherein the vessel is a steam boilerand there are a pair of control devices and a pipe between each controldevice and the boiler with said valve located in each pipe between theboiler and the control device.

manually operable valve located in the pipe between the boiler and theT-junction, said manually operable valve including an operating membermovable from an open position in which the boiler communicates with thetwo pipes leading from the T-junction and a closed position in which theconnection from the boiler is shutoff but an exhaust outlet is openedwhereby the two pipes leading to the T-junction are in communicationwith the atmosphere.

1. In equipment comprising a vessel for containing a liquid, a pipeconnecting said vessel to a control device for controlling the supply ofliquid to said vessel to maintain the liquid in the vessel at asubstantially constant level, an exhaust outlet and a valve located inthe pipe Between the vessel and the control device, which valve isarranged to control the flow of liquid between the control device andthe vessel and between both the control device and the vessel andexhaust, the improvement wherein the valve comprises a valve bodycontaining a chamber, a pair of valve seats within the chamber, whichvalve seats are located between the interior of the chamber andconnections to the vessel and to exhaust, a connection to the controldevice leading from the valve chamber between the valve seats, and avalve-operating member comprising a stem and a head, the head beingmovable between a pair of limiting positions in each of which it is inengagement with one of the valve seats to close either the connection tothe vessel or the connection to exhaust and the valve head beingarranged so that, in each limiting position and in any intermediateposition, it does not close the connection to the control device. 2.Equipment according to claim 1 wherein the valve chamber is of elongatedform with the valve seats located one at each end of the chamber and thevalve-operating member is movable axially of the chamber.
 3. Equipmentaccording to claim 1 wherein the valve chamber is of generallycylindrical form with the valve seats located diametrically oppositeeach other, the head of the valve-operating member being rotatablebetween its limiting positions and stop means being provided forpreventing movement of the operating member beyond its limitingpositions.
 4. Equipment according to claim 1 wherein the vessel is asteam boiler and there are a pair of control devices and a pipe betweeneach control device and the boiler with said valve located in each pipebetween the boiler and the control device.
 5. Equipment according toclaim 4 wherein the control devices include chambers containing floatvalves.
 6. Equipment according to claim 4 wherein the control devicesinclude electronic sensing devices.
 7. Equipment according to claim 5 inwhich there is a line extending from the top of the boiler to the top ofeach float chamber, said line comprising a first pipe extending from theboiler and a T-junction to which pipes extending to the two floatchambers are connected.
 8. Equipment according to claim 7 wherein thereis a manually operable valve located in the pipe between the boiler andthe T-junction, said manually operable valve including an operatingmember movable from an open position in which the boiler communicateswith the two pipes leading from the T-junction and a closed position inwhich the connection from the boiler is shut off but an exhaust outletis opened whereby the two pipes leading to the T-junction are incommunication with the atmosphere.